A cylindrical printing plate formed with high precision and used for printing on a metal can body, particularly an aluminum or aluminum alloy can body. The forming method of a printing plate forms the printing plate to be mounted on an outer periphery of a cylindrical plate cylinder, and includes a notch forming step of forming a positioning notch in a rectangular elastic material sheet in which a resin layer to be served as a plate section is formed on one surface. A cylindrical material forming step rolls the elastic material sheet in which the positioning notch is formed and overlaps both end portions of the elastic material sheet and joining them in a cylindrical shape. A plate section engraving step engraves a printing pattern on the plate section of the elastic material sheet formed into a cylinder shape.

A cylindrical printing plate formed with high precision and used for printing on a metal can body, particularly an aluminum or aluminum alloy can body. The forming method of a printing plate forms the printing plate to be mounted on an outer periphery of a cylindrical plate cylinder, and includes a notch forming step of forming a positioning notch in a rectangular elastic material sheet in which a resin layer to be served as a plate section is formed on one surface. A cylindrical material forming step rolls the elastic material sheet in which the positioning notch is formed and overlaps both end portions of the elastic material sheet and joining them in a cylindrical shape. A plate section engraving step engraves a printing pattern on the plate section of the elastic material sheet formed into a cylinder shape.

There is described a method for manufacturing intaglio printing plates for the production of security papers, wherein a laser beam (2) is used to engrave intaglio printing patterns (3, 3.1, 3.2, 3.3) directly into the surface of a laser-engravable, especially metallic, printing plate medium (1), wherein laser engraving of the printing plate medium (1) is carried out layer by layer in several individual engraving steps performed one after the other in register so that the intaglio printing patterns (3, 3.1, 3.2, 3.3) are gradually engraved into the surface of the printing plate medium (1) up to desired engraving depths, the surface of the engraved printing plate medium (1) being cleaned from residues of the laser engraving process following and between each individual engraving step.

Provided are a lithographic printing plate precursor for furnishing a lithographic printing plate in which adhesion to interleaving paper is prevented, contamination inside a device is prevented, and edge stain does not occur; a method of producing the same; and a printing method using the same. The lithographic printing plate precursor includes: a support; and an image recording layer on the support, in which a region of a surface of the lithographic printing plate precursor at a side of the image recording layer, which is from an end portion of the lithographic printing plate precursor to a portion inside the end portion by 5 mm, contains at least one polymer selected from polyamide, polyurethane, polyurea, polyester and polycarbonate, and has a content of the polymer per unit area which is greater than a content of the polymer per unit area in a region other than the above-described region by an amount of 10 mg/m.sup.2 or greater.

Provided are a lithographic printing plate precursor for furnishing a lithographic printing plate in which adhesion to interleaving paper is prevented, contamination inside a device is prevented, and edge stain does not occur; a method of producing the same; and a printing method using the same. The lithographic printing plate precursor includes: a support; and an image recording layer on the support, in which a region of a surface of the lithographic printing plate precursor at a side of the image recording layer, which is from an end portion of the lithographic printing plate precursor to a portion inside the end portion by 5 mm, contains at least one polymer selected from polyamide, polyurethane, polyurea, polyester and polycarbonate, and has a content of the polymer per unit area which is greater than a content of the polymer per unit area in a region other than the above-described region by an amount of 10 mg/m.sup.2 or greater.

An apparatus for treating a relief precursor having a back side and a relief side. The apparatus includes a housing, a treating means for treating the relief precursor with at least one liquid, a removal means for removing debris and/or liquid from the relief precursor, the removal means arranged downstream of the treating means, and a conveying mechanism configured for transporting the relief precursor in a transport direction through the housing. The removal means includes a liquid removal and guidance body mounted for removing liquid from the back side of the relief precursor. The conveying mechanism is configured for pulling the relief precursor over and against said liquid removal and guidance body whilst the relief precursor is moved in the transport direction, such that in operation liquid is removed from the back side.

Some examples include checking the quality of printed products that are consecutively produced by multiple printing presses to have at least three printed patterns spaced apart from one another. The printed patterns are printed using different printing processes, such as a steel engraving process, an offset printing process, and a screen printing process that may be used for printing the three printed patterns of each printed product. A screen printing press is used for the screen printing process, with multiple steel plates being alternately used in the same production operation for the steel engraving process in an intaglio printing press. For at least two of the steel plates involved in carrying out the steel engraving process, a processing unit may selectively ascertain the deviation of the respective value of the relevant distances associated with the printed patterns, which may be instantaneously ascertained from a defined scale.

An apparatus for treating a relief plate precursor, such as a printing plate precursor, preferably with a liquid. The apparatus includes a transport system with at least one, preferably at least two transport bars; a plate coupling station configured for coupling a relief plate precursor to the transport bar; a treatment compartment configured for treating the relief plate precursor; and a plate decoupling station configured for decoupling the treated relief plate precursor from the transport bar. The transport system is configured to automatically move each transport bar, after being coupled to a relief plate precursor in the plate coupling station, from the plate coupling station through the treatment station to the plate decoupling station, and, after being decoupled from a treated relief plate precursor, from the plate decoupling station back to the plate coupling station, such that the transport bar moves in a closed loop through the apparatus.

An apparatus for treating a relief plate precursor, such as a printing plate precursor, preferably with a liquid. The apparatus includes a transport system with at least one, preferably at least two transport bars; a plate coupling station configured for coupling a relief plate precursor to the transport bar; a treatment compartment configured for treating the relief plate precursor; and a plate decoupling station configured for decoupling the treated relief plate precursor from the transport bar. The transport system is configured to automatically move each transport bar, after being coupled to a relief plate precursor in the plate coupling station, from the plate coupling station through the treatment station to the plate decoupling station, and, after being decoupled from a treated relief plate precursor, from the plate decoupling station back to the plate coupling station, such that the transport bar moves in a closed loop through the apparatus.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.